Commit 56c2cb10 authored by Costa Shulyupin's avatar Costa Shulyupin Committed by Thomas Gleixner
Browse files

hrtimer: Select housekeeping CPU during migration 



During CPU-down hotplug, hrtimers may migrate to isolated CPUs,
compromising CPU isolation.

Address this issue by masking valid CPUs for hrtimers using
housekeeping_cpumask(HK_TYPE_TIMER).

Suggested-by: default avatarWaiman Long <longman@redhat.com>
Signed-off-by: default avatarCosta Shulyupin <costa.shul@redhat.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarWaiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20240222200856.569036-1-costa.shul@redhat.com
parent b2cf7507

kernel/time/hrtimer.c

+2 −1
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include <linux/sched/deadline.h>

#include <linux/sched/nohz.h>

#include <linux/sched/debug.h>

#include <linux/sched/isolation.h>

#include <linux/timer.h>

#include <linux/freezer.h>

#include <linux/compat.h>
@@ -2225,8 +2226,8 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, 


int hrtimers_cpu_dying(unsigned int dying_cpu)

{

	int i, ncpu = cpumask_any_and(cpu_active_mask, housekeeping_cpumask(HK_TYPE_TIMER));

	struct hrtimer_cpu_base *old_base, *new_base;

	int i, ncpu = cpumask_first(cpu_active_mask);



	tick_cancel_sched_timer(dying_cpu);